Pump regulator



V. ROOSA PUMP REGULATOR Nov. 23, 1965 2 Sheets-Sheet l Filed-July 12, 1963 A N RO mR A ,l WN m R w N W wl s E HLM mM ww \\1 Il mw v NN I, r. N mm S wm www r mw Nm wm. 5 NJ mw Ju KN N l. a nhl' N wm mw QN N\ NN O \\1 BY www Mfg/ya ATTORNEYS V. D. ROOSA PUMP REGULATOR Nov. 23, 1965 2 Sheets-Sheet 2 Filed July l2, 1963 WEF INVENTOR VERNON D. ROOSA ATTORNEYS United States Patent O 3,219,020 PUMP REGULATOR Vernon D. Roosa, West Hartford, Conn. Hartford Machine Screw Co., P.0. Box 1440, Hartford, Conn.) Filed July 12, 1963, Ser. No. 294,599 4 Claims. (Cl. 123--140) The present invention relates to Huid pumps having notable usefulness in fuel injection systems for delivering fuel to an internal combustion engine and more particularly to a pump regulator for controlling the fluid delivery of the pump.

It is a primary aim of the present invention to provide a novel regulator of the type described useful for programming the fuel delivery of an engine fuel injection pump with engine speed.

It is another aim of the present invention to provide a novel regulator for a controllable output fluid pump which restricts the fluid output in accordance with a schedule of fluid ouput versus pump operating speed.

It is a further aim of the present invention to provide for a iiuid pump having a governor controlling the fluid delivery of the pump a new and novel regulator for maintaining the iluid delivery within prescribed limits.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth, and the scope of the application of which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a longitudinal cross sectional view, partly broken away, of a pump embodying a preferred embodiment of the present invention;

FIG. 2 is a transverse cross sectional view of the pump, partly broken away, taken substantially along line 2-2 of FIG. 1; a a a FIG. 3 is a longitudinal crosssectional view, partly broken away, of the pump taken substantially along the line 3 3 of FIG. 2; and

FIG. 4 is a longitudinal cross sectional view of the pump, partly broken away, taken substantially along the line 4-4 of FIG. 3. a

Referring now to the drawings in detail, a fuel pump embodying the present invention is of the type conventionally used in fuel injection systems for supplying measured charges of fuel to the injection nozzles of an internal combustion engine. A pump housing 12 having a cover 14 secured by fasteners 16 rotatably supports a pump rotor 18 to which a pump drive shaft 19 is connected. A vane-type fuel transfer pump 20 driven by therotor 18 has a fuel inlet 22 in communication with a pump inlet 24 mounting a fuel filteri26. The transfer pump delivers fuel under pressure to a transfer pump outlet annulus 27 which communicates with a valve bore 29 of a metering valve 28 via axial passages 30 and 32 and a connecting annulus 34.

A transfer pump pressure regulating valve 35, of the type disclosed and described in my U.S. Patent No. 2,883,934 entitled, Pressure Responsive Valve for Fuel Pumps, which issued April 28, 1959, provides for regulating the outlet pressure of the transfer pump and returns excess fuel to the pump inlet 24. The regulator 35 is designed to provide transfer pump output pressure which increases with engine speed in order to meet the increased fuel requirements of the engine at higher speeds and to provide a fuel pressure usable for operating auxiliary mechanisms of the fuel pump.

A charge pump 36 driven by the rotor 18 includes a pair of opposed plungers 38 reciprocable in a diametral bore 39 in the rotor. The charge pump receives metered ICC fuel from the metering valve 28 via an annulus 40 and a plurality of angularly spaced radial passages 42 adapted for registration with a diagonal inlet passage 44 of the charge pump. Fuel is delivered by the charge pump via an axial bore 46 inthe rotor to a radial distributor passage 48 adapted for timed sequential registration with a plurality of angularly spaced out-let passages 50 appropriately connected to the fuel nozzles of the internal combustion engine. A delivery valve 51 in the rotor bore 46 provides for achieving sharp cutoff of fuel to the nozzles to eliminate fuel dribble into the engine combustion chambers.

An annular internal cam 52 of the charge pump has a plurality of pairs of diametrically opposed camming lobes, and a pair of charge pump rollers 54 and roller shoes 56 positioned intermediate the plungers and the internal cam are mounted for rotation with the rotor to actuate the charge pump plungers 38 inwardly for delivering high pressure fuel to the pump distributor. A plurality of governor flyweights 62 angularly spaced about the pump drive shaft 19 provide a variable bias on a sleeve 64 which urges a governor plate 66 clockwise, as seen in FIG. 1, about a supporting pivot 68. The governor plate is urged in the opposite pivotal direction by a compression spring 70 having a bias adjustable by a lever 72 operated by a `shaft 74 which may be suitably connected to the engine throttle linkage. The governor plate 66 is connected for controlling the angular position of the metering valve 28 by a control arm 76 fixed to the metering valve and by a link 78 pivotally connected to the control arm and normally biased by a tension spring 79 into operative connection with the governor plate 66.

As is well known, the quantity or measure of the charge delivered by the pump is a function of the fuel inlet pressure of the charge pump as measured, for example, in the annulus 40, and is readily controlled by varying the restriction in the fuel passage with the metering valve 28. In the usual manner, the pump governor controls the metering valve to govern an associated engine at a selected speed, and, for example, when the load on the engine increases the governor will respond to increase the fuel delivered to the engine.

In accordance with the present invention, a secondary control of the angular position of the metering valve 28 and, therefore, of the fuel delivery of the pump is provided to restrict the fuel charge to within a measure which varies as a function of engine speed. As the engine torque is a fuctlon of the measure of the charge delivered by the fuel pump to the fuel nozzles, there is consequently obtained a restriction on the engine torque to within a value that varies as a function of engine speed. The present invention, therefore, not only establishes a maximum engine torque with each engine speed, but additionally may be designed to ensure that the combustible fuelair ratio on the engine combustion chambers is within a range providing thermally eiicient combustion.

For limiting the angular position of the metering valve 28, the control arm 76 is provided with a follower extension engageable with a cam 92 machined on a plunger 94. The plunger 94 is reciprocably mounted in a bore 96 in a support 98 and is biased inwardly by a compression spring 100 interposed between the plunger 94 and an adjustable stop 102 threaded into the bore. The support 98 is pivotally retained in the upper portion of the housing cavity by a pivot pin 104 threaded to the support. A fastener 106 threaded to a sleeve 109 secured to the Vsupport 98 provides for pivotally adjusting the support against the bias of a compression spring 108 interposed between the pump housing and the sleeve 109.

A bore 110 in the pump housing, substantially coaxial with the bore 96 of the support 98, reciprocably supports a plunger 112 for engagement with the lower end of the plunger 94. The housing is bored to provide a passage 114 between the annulus 34 and the bore 110, and a plug 116 is threaded into the inner end of the bore 110 to seal the bore against uid leakage and to provide a stop for the plunger 112. As a result, transfer fuel is supplied to the underside of the plunger 112 to urge the plunger 112 and the cam 92 outwardly against the bias of the compression spring 100. Inasmuch as the transfer fuel pressure is a function of engine speed, the reciprocable position of the cam 92 is likewise a function of engine speed, and where the transfer pump pressure increases linearly with engine speed, there is substantially a linear relationship between the cam displacement and the engine speed. Additionally, with the cam frusto-conically shaped as shown there is a linear relationship between the maximum angular displacement of the metering Valve 28 as limited by the cam and the engine speed. This linear relationship can be varied by adjustment of the force of the compression spring 100 with the spring stop 102 and by pivotal adjustment of the support 98 with the fastener 106. Also, it can be seen that by proper selection of the spring rate of the spring 100, the contour of the cam 92 and the transfer pump output pressure curve, any desired relationship of maximum fuel delivery and engine speed is obtainable.

Thus, with the pump regulator of the present invention, the maximum measure of the charge delivered by the pump to the engine can be programmed with engine speed to provide a desirable torque versus speed relationship or to maintain the engine fuel-air ratio within limits having respect for the thermal efficiency of combustion of the engine. Additionally, the pump regulator of the present invention provides a highly accurate and readily adjustable secondary control of the conventional pump metering valve for modifying the normal governor control of the valve. lFurther, the regulator is of a construction compatible with the design and operation of conventional fuel injection pumps.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit 4and scope of the invention, the scope of which is dened in the appended claims.

1. In a fuel injection pump for an internal combustion engine, a fuel transfer pump, means for regulating the transfer fuel pressure to increase with engine speed, a metering valve adjustable for regulating the delivery of fuel by said injection pump, an engine speed responsive governor for adjusting the metering valve, and a fuel limiting device comprising means providing a first bore, a rst plunger reciprocably mounted in the rst bore biased in one reciprocable direction by the transfer fuel pressure, a pivotally mounted support having a second bore in general alignment with the rst bore, means for pivotally adjusting the support, a second plunger reciprocably mounted in the second bore having a camming surface thereon, spring means biasing the second plunger into engagement with the rst plunger and the first plunger against the bias -of the transfer fuel pressure, and cam follower means connected to the metering valve engageable with the camming surface for limiting the metering valve adjustment.

2. In a fuel injection pump for an internal combustion engine, a metering valve adjustable in opening and closing directions for variably metering the fuel delivered by said pump to the engine, an engine speed responsive governor for adjusting the metering valve in its opening and closing directions, and a fuel limiting device comprising, a reciprocable cam, a cam follower mounted on the metering valve engageable with the cam to limit the adjustment of the metering valve in the opening direction by said governor, spring means for urging the cam in one reciprocable direction, and means for urging the cam in the opposite reciprocable direction with a bias which varies with engine speed.

3. In a fuel injection pump for an internal combustion engine, a metering valve rotatable in opening and closing directions for metering the fuel delivered by said pump to the engine, an engine speed responsive governor for angularly adjusting the metering valve, and a fuel limiting device comprising a reciprocable cam, first means urging the cam in one reciprocable direction, second means urging the cam in the other reciprocable direction with a bias which varies with engine speed, and cam follower means mounted on the metering valve for engagement with the cam to limit the angular movement of the metering valve in the opening angular direction by said governor in accordance with the reciprocable position of the cam.

4. In a fuel injection pump for an internal combustion engine, a fuel charge pump for delivering measured charges of fuel for injection, a fuel transfer pump for supplying fuel under pressure to the charge pump, a

metering valve adjustable in opening and closing directions for variably metering the fuel delivered by the transfer pump to the charge pump, regulator means for regulating the transfer fuel pressure to increase with engine speed, an engine speed responsive governor for adjusting the metering valve in its opening and closing directions, and a fuel limiting device comprising a cam mounted for reciprocable movement adjacent the metering valve, a cam follower mounted on the metering valve engageable with the cam for limiting the adjustment of the metering valve in the opening direction by said governor, said cam being biased in one reciprocable direction by the transfer fuel pressure to move the cam away from the cam follower a distance which varies with engine speed, and means for urging the cam against the bias of the transfer fuel pressure to move the cam in the opposite reciprocable direction to limit the adjustment of the metering valve in the opening direction by said governor.

References Cited by the Examiner UNITED STATES PATENTS RICHARD B. WILKINSON, Primary Examiner. 

1. IN A FUEL INJECTION PUMP FOR AN INTERNAL COMBUSTION ENGINE, A FUEL TRANSFER PUMP, MEANS FOR REGULATING THE TRANSFER FUEL PRESSURE TO INCREASE WITH ENGINE SPEED, A METERING VALVE ADJUSTABLE FOR REGULATING THE DELIVERY OF FUEL BY SAID INJECTION PUMP, AN ENGINE SPEED RESPONSIVE GOVERNOR FOR ADJUSTING THE METERING VALVE, AND A FUEL LIMITING DEVICE COMPRISING MEANS PROVIDING A FIRST BORE, A FIRST PLUNGER RECIPROCABLY MOUNTED IN THE FIRST BORE BIASED IN ONE RECIPROCABLE DIRECTION BY THE TRANSFER FUEL PRESSURE, A PIVOTALLY MOUNTED SUPPORT HAVING A SECOND BORE IN GENERAL ALIGNMENT WITH THE FIRST BORE, MEANS FOR PIVOTALLY ADJUSTING THE SUPPORT, A SECOND PLUNGER RECIPROCABLY 